Buffy the Vampire Slayer is best remembered for delivering to us some of the most compelling, memorable, and beloved characters to ever grace television. Among them being Buffy's best pal, Willow Rosenberg played by Alyson Hannigan. In addition to offering a quirky, nerdy charm, Willow gave us some of the most important moments in television history, many of which involved Tara Maclay -- Willow's girlfriend. The two offered network television its first major gay relationship. Beyond the milestones pertaining to their relationship, Willow had some utterly brilliant character development that saw her go from a shy student, to a witch, to a lesbian, to an evil Dark sorcerer hellbent on reducing the earth to an apocalyptic blaze; all in a matter of seven seasons.

The character even spawned the inspirations for some other television favorites, including Chloe from Smallville and Charlie from Supernatural. In many ways, Willow is an exponentially important character in the history of television and she feels doubly important when we consider some of the most shocking facts concerning the character that even diehard fans may not know about. Without further ado, listed below are 15 things about Willow that may be unknown to even the truest of fans of both the show and the character.

15 SHE WAS PLAYED BY A DIFFERENT ACTRESS

Alyson Hannigan is often praised for being one of the only actors in the show's history to appear in every episode of Buffy the Vampire Slayer. However, one fact that often remains overlooked is that there actually is just one episode that she did not make an appearance in: the pilot episode. That is, the original unaired pilot.

In addition to being a means to sell a show, a pilot episode works as a means to let producers see what does work with the show and what doesn't. One of the big things that did not work in the pilot was Riff Regan's performance as Willow Rosenberg. In fact, the one thing the network wanted Joss Whedon to do prior to ordering a full series was replace her. Thus, a new audition process for Willow commenced, and Alyson Hannigan snagged it.

14 XANDER WAS ALMOST GAY INSTEAD OF HER

Willow made history by being one of the first gay main characters to appear on a major television network, but that accolade almost went to another one of Buffy's best friends. When Joss Whedon first created the show, he knew that he wanted one of Buffy's best friends to become gay, but he wasn't sure which one between Xander and Willow.

Perhaps he decided on this around season three when he started foreshadowing Willow's coming out, but there are some early Xander scenes that work as potential foreshadowing if Whedon made Xander gay. In season two when closeted footballer Larry comes out to Xander, he was under the impression that Xander was gay, too. Maybe Whedon foreshadowed both characters potentially coming out to cover his bases.

13 ALYSON HANNIGAN CAN'T SING

Many fans consider the episode "Once More With Feeling" to be the best episode -- if not, the most impressive -- episode of the series since everyone involved had to participate in an elaborate song and dance number. Except, oddly enough, Alyson Hannigan as Willow is the only main character who does not have a big song and dance routine of her own. There is a reason for that.

The reason being that it is simply because Alyson Hannigan herself is not a very good singer. In fact, she can't sing to save her life. When told that Joss Whedon was going to write a completely musical episode of the show, Hannigan begged Whedon to reduce the number of lines she has to sing. And so he did.

12 BUFFY KILLS HER IN THE COMICS

To the surprise of many fans, after being such a lovable Scooby Gang member for so many years, Willow turned into one of Buffy's most formidable foes before season six came to a close. Seeing Willow turn into the Big Bad, Dark Willow, was an unexpected and startling twist in the story. Willow nearly brought about the destruction of the whole world, and it is very likely that she'll do it again.

In the comic book continuation, Buffy finds herself transported to a future where Willow has gone Dark again. Willow is so powerful that the only way that Buffy can stop Willow is to kill her. When the present day Willow is able to bring Buffy back to the present, The Slayer warns Willow of what she saw in the future. Willow is unphased by it because to her, nothing is set in stone; not even the future.

11 WHY SHE'S A REDHEAD

One of the things that helped Willow separate herself from the main three members of the Scooby Gang was her crimson red hair. The funny thing about that is that Alyson Hannigan isn't a redhead in real life and changing Willow's hair color was a last minute decision from Joss Whedon that came when he realized that all of his female lead characters had the same hair color.

As Alyson Hannigan recalled in a 2011 interview, it bothered Whedon that Sarah Michelle Gellar, Charisma Carpenter, and Hannigan all came to the show prior to production with the same auburn brown hair color. He asked if anyone wanted to change their hair color to red, and Hannigan willingly volunteered. It's also worth noting that Gellar's hair actually gets blonder with every season.

10 THE STUDIO WASN'T BEHIND TARA/WILLOW

Joss Whedon took a big risk when he decided to incorporate a homosexual relationship on the show in a time when homosexuality wasn't usually documented on television, yet alone network television. The show's co-executive producer, David Greenwalt, once recalled that he received a phone call from an anonymous Warner Bros. exec asking "Is [Joss] really going to do this gay thing?" after learning about his storyline plans.

When he told the studio he wanted Tara and Willow to have their first on-screen kiss, the studio was reluctant. After they told him to cut the kiss, Whedon declared he would walk away from the show if Tara and Willow didn't get their kiss. So the studio let Tara and Willow have their kiss after all in "The Body."

9 ABOUT HER NEW LOVE INTEREST IN SEASON SEVEN

When Willow started hooking up with Kennedy a few episodes after Tara died, it came to the chagrin of many audiences for a number of reasons. One being that they were not particularly fond of the Kennedy character to begin with. Another being that fans believed it to be too soon that Willow started dating again after her relationship with Tara ending so abruptly.

Despite what critics say about her relationship with Kennedy, Joss Whedon felt it important for Willow to move on from Tara because, as he admitted in a 2003 interview that he didn't want Willow to fall into "typical gay celibacy." Which, essentially, refers to a gay character who isn't in a relationship that reflects their sexual orientation. Whedon wanted to explore more of Willow's relationships and how she could bounce back after Tara.

8 SHE KEPT MAKING HISTORY

Throughout Willow's tenure on the show, she often found a way to make television history in one way or another. Most notably, her milestones were created through her relationship with Tara. Tara and Willow's romance marked the earliest example of a lesbian relationship on network television. Which, in turn, gave audiences the very first lesbian kiss on network television when the two of them smooched for the first time in "The Body."

A couple seasons later, after Tara was killed off, Willow made history with Kennedy in Season 7 by sharing network television's first lesbian hook-up scene. Willow did not only make history through her different romances. She also gave the first reference to Google (as a verb) in television history after asking "Have you Googled her yet?"

7 THERE WAS ORIGINALLY MORE TO THE WILLOW/VERUCA/OZ

Some fans may recall that in season four, a roadblock is put in the relationship between Oz and Willow when the shy werewolf Veruca steps in. Compelled to be with someone who understands his angst of being a werewolf, Oz starts an affair with Veruca. After just three episodes, Veruca is killed off in a battle with Oz, and Oz leaves Sunnydale in hopes of finding a cure to his curse. On the surface, this entire love triangle seemed rushed, but there is a reason for that.

Originally, Joss Whedon planned to extend this storyline throughout the entirety of season four. Plans were quickly changed and rushed through when Seth Green abruptly decided to leave the show. Whedon was heartbroken at Green's sudden departure and decided to use that heartbreak to write Willow and Oz's breakup.

6 TARA ALMOST CAME BACK FOR SEASON SEVEN

Tara's death and departure from the show hit a lot of fans hard, almost as hard as Willow. While we never saw Tara again after she got shot, there were two scenarios that Whedon cooked up to have Amber Benson reprise her role in season seven that never came to fruition. The first idea saw The First come to Willow in the form of Tara to convince Willow to kill herself in the episode "Conversations with Dead People." Benson wasn't available to shoot scenes, so that idea got nixed.

A much lighter idea saw Tara come back at the end of season seven in an episode where Buffy would be granted one life-altering wish with no strings attached. She would have decided on bringing Tara back to life, surprising Willow on the one-year anniversary of Tara's death. Again, Benson was unavailable for filming.

5 HER COMING OUT WAS FORESHADOWED IN SEASON THREE

It has been well documented that some of the most vital and substantial storylines that occurred during the later seasons of Buffy the Vampire Slayer were foreshadowed well in advance during the earliest seasons. This would include Willow's coming out as a lesbian. Her coming out was first foreshadowed in the season three episode "Dopplegangland." In the episode, Willow's evil, sultry vampire version of herself from another universe -- who appeared previously in "The Wish"-- unexpectedly found herself in the Buffyverse.

In addition to Vampire Willow exhibiting some homosexual tendencies of her own, this inspired Willow to say "I'm so evil and skanky. And I think I might be gay" when referring to her evil counterpart. Within the next couple seasons, Willow would become both evil and gay.

4 HER AND TARA HAVE A COMIC BOOK COLLECTION

Willow and Tara's relationship lasted a little over two years/seasons before Tara was suddenly killed off in the blink of an eye. This move disappointed many fans who were hoping to see more of the duo in future episodes. For those who thought that there were not enough Tara and Willow scenes during seasons four, five, and six and are just itching to see more of them together, look no further than the comic book series Willow & Tara.

One of the writers of the series was none other than Tara herself, Amber Benson. Benson also works on these collections alongside writer Christopher Golden, who wrote for both Buffy and Angel, so technically this series is canon. The collection includes three two-part issues following everyone's favorite wiccan couple.

3 SHE BROKE UP WITH KENNEDY TO DATE A SNAKE

For viewers who were not very satisfied with Willow's relationship with Kennedy closing out season seven, it would be a wise investment to tune over to the comic book continuation. It is there where Willow dumps Kennedy for a snake lady. It all started when Willow began training under the aforementioned mysterious snake woman, Aluwyn (aka Saga Vasuki). Eventually, the two start having an affair that leads to them to hooking up.

Speaking of, there's a point where Willow magically contacts Aluwyn while being with Kennedy. Willow also learns that Aluwyn was not actually the guide she was meant to train under, but merely a trickster. Still, Willow winds up breaking up with Kennedy because of her love for Aluwyn, who she later reconnects with in Wonderland.

2 SHE WAS LOBOTOMIZED BY AMY AND WARREN

Audiences should remember Warren as The Big Bad of season six who accidentally shot Tara, leading Willow to turn into Dark Willow and skin him of his flesh, killing Warren in the process. Audiences should also remember Amy as the wiccan who spent a couple seasons as Willow's pet rat who reverted back to a human being and got Willow addicted to magic. The two parted ways, but Amy returns in the comic book continuation.

She doesn't come alone either, as she kidnaps Willow with Warren, who's been brought back from the dead without his skin intact. To get revenge on Willow, they aligned themselves with the US Military and lobotomized Willow. Buffy manages to rescue Willow and after the Seed of Wonder is destroyed, Warren is killed off.

1 DARK WILLOW BECAME A RUNNING GAG

In the short time that Willow spent as an evil, dark being in season six, she caused a lot of damage that none of the other Scoobies were able to forget. As a result, they never let Willow forget it either. So much so that they constantly refer to that time in Willow's life as "going dark" or "going Dark Willow" in the comics.

When Xander becomes an unwilling assistant to Dracula upon the vamp kidnapping him, Andrew says that he's afraid Xander was "going Dark Willow," which irks Willow. It irks her even more later to hear Dawn say she hoped Spike did not "go Dark Willow." The running gag went on for so long that Willow could not help herself but inadvertently utter the "going Dark Willow" phrase herself at one point.